Innovation News

New York, NY ― Ron Winslow reports in The Wall Street Journal that two research teams reported in separate studies that for the first time they were able to grow human embryos outside the uterus for up to 13 days, an accomplishment that opens a new window on the earliest stages of human development while pushing the limits of embryonic research.

Scientists said the studies provide the first look at the critical biological processes that occur when an embryo attaches to the uterus and begins to organize into structures that become the heart, the brain and other organs.

Much is known about the embryo’s first seven days, after which it would typically be implanted in the uterus. But researchers have been unable to study in humans what happens during and immediately after that.

“This is the period of our lives that some of the most important [biological] decisions are made,” said Magdalena Zernicka-Goetz, professor of mammalian development and stem-cell biology at University of Cambridge in the U.K. and senior author of one of the studies. “It was entirely a black box of development that we were not able to access until now.”

​Her report was published online Wednesday by the journal Nature Cell Biology.

One of the key findings from the studies was that early embryonic development is significantly different in humans than in animals such as mice, where the process has been extensively studied.

In addition, to both teams’ surprise, the embryos outside the womb were able to “self-organize” or begin to set in motion early development of key body organs without any biological cues from the mother.

Eventually the insights gained could identify new ways to use stem cells to test drugs and treat injury and disease, researchers said.

In both studies, researchers stopped growing the embryos before the 14th day after fertilization — the point after which a key change in development occurs — to keep within international regulations.

The 14-day rule, initially proposed in 1979 by an ethics panel in the U.S., hadn’t come close to being broached before.